Focal segmental glomerulosclerosis (FSGS) is a clinical-pathologic syndromes characterized by the accumulation of fibrotic proteins in glomeruli, initially involving only some glomeruli (focal) and involving portions (segments) of the affected glomeruli. FSGS can be classified as follows: idiopathic FSGS, genetic FSGS and post-adaptive FSGS (associated with glomerular hypertrophy and hyperfiltration, and due to reduced renal mass, renal toxins, obesity, and sickle cell disease). A related syndrome is collapsing glomerulopathy, associated with podocyte hyperplasia whereas FSGS is associated with podocyte depletion. Collapsing glomerulopathy can be classified as HIV-associated or idiopathic. Many patients with podocyte diseases, including minimal change nephropathy (MCN), FSGS, and collapsing glomerulopathy are refractory to all conventional remittive therapy. Current studies: * ritiuximab + cyclosporine: single center, open label * sparsentan: multicenter, placebo-controlled RCT, industry-sponsored (IRB submission pending) * MaNAc: phase 1B, single center, open label for pharmacokinetics and response (IRB submission pending, CRADA with New Zealand Pharmaceuticals pending)